A star's temperature and color depend directly on
how big the star is. The bigger a star is the hotter it will
be. This is because the stronger gravity of larger stars causes
them to burn their fuel more quickly, raising the star's temperature.

How can gravity make a star burn its fuel faster?

The stronger an object's gravity is, the more power
it has to pull its mass inward. This causes the core to be very
compact, and creates a lot of extra pressure. This extra
pressure builds up, raising the temperature of the core. The
hotter the core gets, the more of its hydrogen fuel it will burn.

Star Life:

Because large stars burn their fuel quicker than
smaller stars, they run out of fuel sooner. This means that
larger stars do not live as long as small stars. In other
words, the smaller a star is, the longer it will live. Our Sun
will live about 10 Billion years. It is already 5 Billion years
old, meaning it will live another 5 Billion years. Some very
large O stars only live a few hundred thousand years, while the very
small M stars can live for trillions of years.

Assignment # 3.

How does a star's size affect its color and
temperature? Please explain why.